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AMH Aged Care Companion
Constipation
Before starting treatment
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Constipation in older people is commonly associated with immobility
and/or decreased fluid and fibre intake. Although whole gut transit
time is unchanged in healthy, active older people, it is prolonged in
immobile people. Other contributing factors include social conditions
(eg lack of privacy, reliance on others for toileting assistance, change in
surroundings), drugs, cognitive status and medical conditions
(eg hypothyroidism, neurological disease, depression, perianal
conditions).
In older people, constipation may present as confusion, overflow
diarrhoea, abdominal pain, urinary retention, nausea or loss of
appetite.
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Assess for faecal impaction and consider need for referral to exclude
colon cancer in older patients with alarm symptoms or sudden change
in bowel habit.
Treat reversible causes, eg dehydration, depression, hypothyroidism,
hypercalcaemia.
The relationship between urinary incontinence and constipation can be
complex: constipation may exacerbate urinary incontinence and
treatment of urinary incontinence can lead to constipation, eg if fluid
intake is decreased in an attempt to control urinary incontinence or if
anticholinergic drugs are used. Assess for and manage urinary
incontinence, see Urinary incontinence p 172.
Stop causative drugs if possible, eg aluminium antacids, opioids, drugs
with anticholinergic effects (p 236), calcium or iron supplements,
diuretics, verapamil.
Ensure an accurate bowel chart is kept, recording time, amount and
consistency of stool; this is useful for assessing when laxatives are
required and response to treatment.
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Non-drug treatment
Usually the first step in management, although evidence is limited;
should be continued even if laxatives are used:
– ensure adequate fluid intake (but consider risk of fluid overload
in people with heart failure or renal impairment)
– ensure adequate dietary fibre intake; increase intake gradually
to avoid bloating and flatulence; consider dietetic review
– toilet after meals or hot drink when gastrocolic reflex is maximal
– increase exercise within the person’s abilities
– improve access to toileting facilities
– advise unhurried, complete defecation.
For more detailed drug information, see the current edition of the Australian Medicines Handbook
© Australian Medicines Handbook Pty Ltd
www.amh.net.au
AMH Aged Care Companion
Drug treatment
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Management of constipation remains largely empirical; evidence
supporting the use of laxatives is poor, particularly in the elderly.
Both fibre and laxatives modestly improve bowel movement frequency
in adults with constipation. There is inadequate evidence to establish
whether fibre is superior to laxatives, or whether one laxative class is
superior to another. Drug choice may be based on required onset of
action, patient preference, adverse effects, effectiveness of previous
treatments and cost, see Table 8 Comparison of laxative classes p 142.
Whilst some cases of constipation may resolve with short-term use of
laxatives, chronic laxative use is often required (eg in opioid-induced
constipation, progressive neurological conditions, immobility); titrate
dose to minimum required to achieve desired effect.
Rapid relief of constipation: initial management of moderate-to-severe
constipation may include suppositories, enemas, macrogol or saline
laxatives to clear the rectum, followed by ongoing management.
Ongoing management of constipation: promote regular bowel habits by
using small regular doses of laxatives. Try bulk-forming laxatives for
people who have a low-fibre diet, adequate fluid intake and are mobile.
Osmotic and/or stimulant laxatives may be more appropriate for
immobile people and those with decreased fluid intake.
Opioid-induced constipation can be anticipated, so begin regular laxatives
when starting opioid analgesia. Agents of choice include combined
stimulant with stool softener (eg Coloxyl with Senna®) or osmotic
laxatives (eg sorbitol or lactulose). Avoid bulk-forming laxatives and a
high-fibre diet as increasing bulk may cause obstruction. For resistant
cases use glycerol suppositories, small volume enemas, a macrogol
laxative (eg Movicol®) or a saline laxative (see Safety considerations
below). For palliative care patients, methylnaltrexone may be
considered, see Palliative care issues p 71.
Faecal impaction often presents as faecal soiling or overflow diarrhoea
(usually small volume); management may include high-dose oral
macrogol laxatives, suppositories, enemas and manual evacuation.
Antidiarrhoeal agents should not be used to stop overflow diarrhoea.
Regular laxatives may be required once impaction has been alleviated
in addition to any lifestyle and dietary changes that can be made.
Aged Care Companion © AMH 2016
© Australian Medicines Handbook Pty Ltd
Constipation
www.amh.net.au
AMH Aged Care Companion
Table 8 Comparison of laxative classes
Laxative
class
Example
Onset of
action
Place in treatment and
safety considerations
2–3 days
• ensure adequate fluid intake
• contraindicated in intestinal
obstruction, impaction, colonic
atony; avoid in dysphagia
• avoid in immobile or fluidrestricted older patients as can
worsen constipation
1–3 days
• use in opioid-induced
constipation
• contraindicated in intestinal
obstruction
• not suitable for acute relief of
constipation due to slow onset of
effect
• flatulence is common
ispaghula husk
(eg Fybogel®)1;
psyllium (eg
Metamucil®)1;
sterculia (eg
Normafibe®)1
sorbitol
(eg Sorbilax®)2;
lactulose (eg
Duphalac®)2
macrogol
laxatives (eg
Movicol®
products);
saline laxatives
containing
magnesium (eg
Epsom Salts,
Magnesia S
Pellegrino®)1
0.5–3 hrs;
1–3 days
(macrogol)
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osmotic
laxatives
stool
softeners
1
2
3
4
docusate
(Coloxyl®)3
• some macrogol laxatives can be
used for faecal impaction and
constipation
• magnesium salts are not
recommended for regular use
• limited evidence suggests
macrogol laxatives may be more
effective, and better tolerated,
than lactulose in chronic
constipation
• risk of electrolyte disturbance
and dehydration (less of a risk
with macrogol laxatives than
others, eg saline laxatives); use
with caution in older people and
in renal impairment or
cardiovascular disease
• contraindicated in intestinal
obstruction (partial or complete),
bowel perforation or threatened
perforation (eg colitis), severe
colitis (especially toxic
megacolon)
• avoid sodium phosphatecontaining laxatives, see Safety
considerations p 143
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bulkforming
laxatives
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Oral laxatives
2–3 days
• may be used to reduce straining,
eg in rectal surgery, acute perianal disease, ischaemic heart
disease
• use for opioid-induced
constipation in combination with
a stimulant laxative (eg Coloxyl
with Senna®)
dose according to label
15–30 mL once daily adjusted according to clinical response
50–150 mg once or twice daily up to 480 mg/day in divided doses
2.8 g rectally; allow to remain for 15–30 minutes
For more detailed drug information, see the current edition of the Australian Medicines Handbook
© Australian Medicines Handbook Pty Ltd
www.amh.net.au
AMH Aged Care Companion
Laxative
class
Example
Onset of
action
Place in treatment and
safety considerations
6–12 hrs
• can be used for acute or chronic
(eg in neuromuscular disease)
constipation
• contraindicated in intestinal
obstruction, acute abdominal
conditions and inflammatory
bowel disease
• may cause abdominal discomfort
and cramping
• increased risk of faecal incontinence in elderly patients
• ensure adequate fluid intake
with products that also contain a
bulk-forming laxative (eg
Normacol Plus®, Agiolax®)
stimulant
laxatives
bisacodyl (eg
Bisalax®)1;
frangula bark
(in Normacol
Plus®)1;
senna (eg
Senokot®)1
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Oral laxatives (continued)
Rectal laxatives
glycerol
suppository4;
saline
microenema
(eg Microlax®)
5–30 mins
(glycerol);
2–30 mins
(saline
laxatives)
stimulant
laxatives
bisacodyl
microenema or
suppository (eg
Bisalax®)
5–60 mins
1
2
3
4
• rectal laxatives may be indicated
for occasional use, eg in faecal
impaction or if there is
insufficient response to oral
laxatives
• avoid embedding suppositories
in faecal matter (delays effect)
• avoid sodium phosphate enema
(eg Fleet®), see Safety
considerations p 143
co
osmotic
laxatives
dose according to label
15–30 mL once daily adjusted according to clinical response
50–150 mg once or twice daily up to 480 mg/day in divided doses
2.8 g rectally; allow to remain for 15–30 minutes
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Safety considerations
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Saline laxatives contain ions such as magnesium, sulfate, phosphate
and citrate; they may cause electrolyte disturbances. Use with caution
in older people, and avoid in renal impairment or cardiovascular
disease.
Laxatives containing sodium phosphate (eg Fleet®, Diacol®) should not
be used in the elderly; they can cause serious fluid and electrolyte
disturbance, including hypocalcaemia, hyperphosphataemia and
hypokalaemia. Acute renal failure (including acute phosphate
nephropathy), cardiac arrest and deaths have been reported. There is a
greater risk of adverse effects in patients >55 years, in dehydrated
patients, or in those being treated with diuretics, ACE inhibitors,
sartans or NSAIDs. Sodium phosphate laxatives are contraindicated in
heart failure or renal impairment.
Some macrogol products contain sodium (eg Movicol® contains
approximately 8.1 mmol (186 mg) sodium per sachet; Movicol-Half®
and Movicol Junior® sachets contain approximately half this); consider
impact of sodium intake in certain patients (eg those with heart failure).
Aged Care Companion © AMH 2016
© Australian Medicines Handbook Pty Ltd
Constipation
www.amh.net.au
AMH Aged Care Companion
Practice points
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glycerol is also known as glycerin
laxatives are also referred to as aperients
encourage person to sit on the toilet with both feet supported on
floor or foot stool, leaning forward slightly so abdomen falls away
from body relaxing pelvic floor muscles, as this will help reduce
the need for straining
stool softeners have little value used alone in chronic constipation
or constipation from opioids
be aware of difficulties for older people in the community or lowlevel care facilities; they may not use non-drug options because:
– they feel unsafe going out alone to exercise
– fruit and vegetables may be too expensive
– they believe increased fluid intake may worsen urinary
incontinence
cost may be a problem, especially if long-term laxative use is
needed; not all laxatives are subsidised by the PBS and restrictions
may apply to those that are
there is no convincing evidence that chronic use of stimulant
laxatives causes atony, aperistaltic colon or colonic injury
prucalopride is approved for treatment of chronic idiopathic
constipation when other regular laxatives are inadequate; in a
4-week study in people >65 years (70% female), the recommended
dose was not significantly better than placebo in achieving the
primary endpoint (3 or more spontaneous complete bowel
movements per week) at any point during the trial; further study
is needed to establish its role in the management of constipation
in older people
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For more detailed drug information, see the current edition of the Australian Medicines Handbook
© Australian Medicines Handbook Pty Ltd
www.amh.net.au